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Jha R, Bernstock JD, Chalif JI, Hoffman SE, Gupta S, Guo H, Lu Y. Updates on Pathophysiology of Discogenic Back Pain. J Clin Med 2023; 12:6907. [PMID: 37959372 PMCID: PMC10647359 DOI: 10.3390/jcm12216907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/15/2023] Open
Abstract
Discogenic back pain, a subset of chronic back pain, is caused by intervertebral disc (IVD) degeneration, and imparts a notable socioeconomic health burden on the population. However, degeneration by itself does not necessarily imply discogenic pain. In this review, we highlight the existing literature on the pathophysiology of discogenic back pain, focusing on the biomechanical and biochemical steps that lead to pain in the setting of IVD degeneration. Though the pathophysiology is incompletely characterized, the current evidence favors a framework where degeneration leads to IVD inflammation, and subsequent immune milieu recruitment. Chronic inflammation serves as a basis of penetrating neovascularization and neoinnervation into the IVD. Hence, nociceptive sensitization emerges, which manifests as discogenic back pain. Recent studies also highlight the complimentary roles of low virulence infections and central nervous system (CNS) metabolic state alteration. Targeted therapies that seek to disrupt inflammation, angiogenesis, and neurogenic pathways are being investigated. Regenerative therapy in the form of gene therapy and cell-based therapy are also being explored.
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Affiliation(s)
- Rohan Jha
- Harvard Medical School, Boston, MA 02115, USA
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Joshua D. Bernstock
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Joshua I. Chalif
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Samantha E. Hoffman
- Harvard Medical School, Boston, MA 02115, USA
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Saksham Gupta
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Hong Guo
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
| | - Yi Lu
- Department of Neurosurgery, Brigham and Women’s Hospital, Boston, MA 02115, USA
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Stover JD, Trone MAR, Weston J, Lewis C, Levis H, Philippi M, Zeidan M, Lawrence B, Bowles RD. Therapeutic TNF-alpha Delivery After CRISPR Receptor Modulation in the Intervertebral Disc. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.542947. [PMID: 37398456 PMCID: PMC10312567 DOI: 10.1101/2023.05.31.542947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Low back pain (LBP) ranks among the leading causes of disability worldwide and generates a tremendous socioeconomic cost. Disc degeneration, a leading contributor to LBP, can be characterized by the breakdown of the extracellular matrix of the intervertebral disc (IVD), disc height loss, and inflammation. The inflammatory cytokine TNF-α has multiple pathways and has been implicated as a primary mediator of disc degeneration. We tested our ability to regulate the multiple TNF-α inflammatory signaling pathways in vivo utilizing CRISPR receptor modulation to slow the progression of disc degeneration in rats. Sprague-Dawley rats were treated with CRISPRi-based epigenome-editing therapeutics targeting TNFR1 and showed a decrease in behavioral pain in a disc degeneration model. Surprisingly, while treatment with the vectors alone was therapeutic, TNF-α injection itself became therapeutic after TNFR1 modulation. These results suggest direct inflammatory receptor modulation, to harness beneficial inflammatory signaling pathways, as a potent strategy for treating disc degeneration.
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Stover JD, Trone MA, Lawrence B, Bowles RD. Multiplex epigenome editing of ion channel expression in nociceptive neurons abolished degenerative IVD-conditioned media-induced mechanical sensitivity. JOR Spine 2023; 6:e1253. [PMID: 37361323 PMCID: PMC10285767 DOI: 10.1002/jsp2.1253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 01/15/2023] [Accepted: 02/27/2023] [Indexed: 06/28/2023] Open
Abstract
Background Low back pain is a major contributor to disability worldwide and generates a tremendous socioeconomic impact. The degenerative intervertebral disc (IVD) has been hypothesized to contribute to discogenic pain by sensitizing nociceptive neurons innervating the disc to stimuli that is nonpainful in healthy patients. Previously, we demonstrated the ability of degenerative IVDs to sensitize neurons to mechanical stimuli; however, elucidation of degenerative IVDs discogenic pain mechanisms is required to develop therapeutic strategies that directly target these mechanisms. Aims In this study, we utilized CRISPR epigenome editing of nociceptive neurons to identify mechanisms of degenerative IVD-induced changes to mechanical nociception and demonstrated the ability of multiplex CRISPR epigenome editing of nociceptive neurons to modulate inflammation-induced mechanical nociception. Methods and Results Utilizing an in vitro model, we demonstrated degenerative IVD-produced IL-6-induced increases in nociceptive neuron activity in response to mechanical stimuli, mediated by TRPA1, ASIC3, and Piezo2 ion channel activity. Once these ion channels were identified as mediators of degenerative IVD-induced mechanical nociception, we developed singleplex and multiplex CRISPR epigenome editing vectors that modulate endogenous expression of TRPA1, ASIC3, and Piezo2 via targeted gene promoter histone methylation. When delivered to nociceptive neurons, the multiplex CRISPR epigenome editing vectors abolished degenerative IVD-induced mechanical nociception while preserving nonpathologic neuron activity. Conclusion This work demonstrates the potential of multiplex CRISPR epigenome editing as a highly targeted gene-based neuromodulation strategy for the treatment of discogenic pain, specifically; and, for the treatment of inflammatory chronic pain conditions, more broadly.
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Affiliation(s)
- Joshua D. Stover
- Department of BioengineeringUniversity of UtahSalt Lake CityUtahUSA
| | - Matthew A. Trone
- Department of BioengineeringUniversity of UtahSalt Lake CityUtahUSA
| | - Brandon Lawrence
- Department of OrthopaedicsUniversity of UtahSalt Lake CityUtahUSA
| | - Robby D. Bowles
- Department of BioengineeringUniversity of UtahSalt Lake CityUtahUSA
- Department of OrthopaedicsUniversity of UtahSalt Lake CityUtahUSA
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Wang F, Guo K, Nan L, Wang S, Lu J, Wang Q, Ba Z, Huang Y, Wu D. Kartogenin-loaded hydrogel promotes intervertebral disc repair via protecting MSCs against reactive oxygen species microenvironment by Nrf2/TXNIP/NLRP3 axis. Free Radic Biol Med 2023; 204:128-150. [PMID: 37149010 DOI: 10.1016/j.freeradbiomed.2023.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/08/2023]
Abstract
Intervertebral disc (IVD) degeneration (IDD) and the consequent low back pain present a major medical challenge. Stem cell-based tissue engineering is promising for the treatment of IDD. However, stem cell-based treatment is severely impaired by the increased generation of reactive oxygen species (ROS) in degenerative disc, which can lead to a high level of cell dysfunction and even death. In this study, a kartogenin (KGN)@PLGA-GelMA/PRP composite hydrogel was designed and used as a carrier of ADSCs-based therapies in disc repair. Injectable composite hydrogel act as a carrier for controlled release of KGN and deliver ADSCs to the degenerative disc. The released KGN can stimulate the differentiation of ADSCs into a nucleus pulposus (NP) -like phenotype and boost antioxidant capacity of ADSCs via activating Nrf2/TXNIP/NLRP3 axis. Furthermore, the composite hydrogel combined with ADSCs attenuated the in vivo degeneration of rat IVDs, maintained IVD tissue integrity and accelerated the synthesis of NP-like extracellular matrix. Therefore, the KGN@PLGA-GelMA/PRP composite hydrogel is a promising strategy for stem cell-based therapies of IDD.
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Affiliation(s)
- Feng Wang
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Kai Guo
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Liping Nan
- Center for Orthopaedic Science and Translational Medicine, Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, China
| | - Shuguang Wang
- Emergency Center, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221004, China
| | - Jiawei Lu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Qiang Wang
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China
| | - Zhaoyu Ba
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.
| | - Yufeng Huang
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.
| | - Desheng Wu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, 200120, China.
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Tang SN, Bonilla AF, Chahine NO, Colbath AC, Easley JT, Grad S, Haglund L, Le Maitre CL, Leung V, McCoy AM, Purmessur D, Tang SY, Zeiter S, Smith LJ. Controversies in spine research: Organ culture versus in vivo models for studies of the intervertebral disc. JOR Spine 2022; 5:e1235. [PMID: 36601369 PMCID: PMC9799089 DOI: 10.1002/jsp2.1235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022] Open
Abstract
Intervertebral disc degeneration is a common cause of low back pain, the leading cause of disability worldwide. Appropriate preclinical models for intervertebral disc research are essential to achieving a better understanding of underlying pathophysiology and for the development, evaluation, and translation of more effective treatments. To this end, in vivo animal and ex vivo organ culture models are both widely used by spine researchers; however, the relative strengths and weaknesses of these two approaches are a source of ongoing controversy. In this article, members from the Spine and Preclinical Models Sections of the Orthopedic Research Society, including experts in both basic and translational spine research, present contrasting arguments in support of in vivo animal models versus ex vivo organ culture models for studies of the disc, supported by a comprehensive review of the relevant literature. The objective is to provide a deeper understanding of the respective advantages and limitations of these approaches, and advance the field toward a consensus with respect to appropriate model selection and implementation. We conclude that complementary use of several model types and leveraging the unique advantages of each is likely to result in the highest impact research in most instances.
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Affiliation(s)
- Shirley N. Tang
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Andres F. Bonilla
- Preclinical Surgical Research Laboratory, Department of Clinical SciencesColorado State UniversityFort CollinsColoradoUSA
| | - Nadeen O. Chahine
- Departments of Orthopedic Surgery and Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
| | - Aimee C. Colbath
- Department of Clinical Sciences, College of Veterinary MedicineCornell UniversityIthacaNew YorkUSA
| | - Jeremiah T. Easley
- Preclinical Surgical Research Laboratory, Department of Clinical SciencesColorado State UniversityFort CollinsColoradoUSA
| | | | | | | | - Victor Leung
- Department of Orthopaedics and TraumatologyThe University of Hong KongHong KongSARChina
| | - Annette M. McCoy
- Department of Veterinary Clinical MedicineUniversity of IllinoisUrbanaIllinoisUSA
| | - Devina Purmessur
- Department of Biomedical EngineeringThe Ohio State UniversityColumbusOhioUSA
| | - Simon Y. Tang
- Department of Orthopaedic SurgeryWashington University in St LouisSt LouisMissouriUSA
| | | | - Lachlan J. Smith
- Departments of Orthopaedic Surgery and NeurosurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA,Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvaniaUSA
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Lorentzian-Corrected Apparent Exchange-Dependent Relaxation (LAREX) Ω-Plot Analysis-An Adaptation for qCEST in a Multi-Pool System: Comprehensive In Silico, In Situ, and In Vivo Studies. Int J Mol Sci 2022; 23:ijms23136920. [PMID: 35805925 PMCID: PMC9266897 DOI: 10.3390/ijms23136920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/05/2022] [Accepted: 06/20/2022] [Indexed: 12/14/2022] Open
Abstract
Based on in silico, in situ, and in vivo studies, this study aims to develop a new method for the quantitative chemical exchange saturation transfer (qCEST) technique considering multi-pool systems. To this end, we extended the state-of-the-art apparent exchange-dependent relaxation (AREX) method with a Lorentzian correction (LAREX). We then validated this new method with in situ and in vivo experiments on human intervertebral discs (IVDs) using the Kendall-Tau correlation coefficient. In the in silico experiments, we observed significant deviations of the AREX method as a function of the underlying exchange rate (kba) and fractional concentration (fb) compared to the ground truth due to the influence of other exchange pools. In comparison to AREX, the LAREX-based Ω-plot approach yielded a substantial improvement. In the subsequent in situ and in vivo experiments on human IVDs, no correlation to the histological reference standard or Pfirrmann classification could be found for the fb (in situ: τ = −0.17 p = 0.51; in vivo: τ = 0.13 p = 0.30) and kba (in situ: τ = 0.042 p = 0.87; in vivo: τ = −0.26 p = 0.04) of Glycosaminoglycan (GAG) with AREX. In contrast, the influence of interfering pools could be corrected by LAREX, and a moderate to strong correlation was observed for the fractional concentration of GAG for both in situ (τ = −0.71 p = 0.005) and in vivo (τ = −0.49 p < 0.001) experiments. The study presented here is the first to introduce a new qCEST method that enables qCEST imaging in systems with multiple proton pools.
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